surging and alternator problems


New Member
Jun 14, 2004
Got a 89 lx that has a 92 5.0 motor in it, every since i bought it it would surge at idle and the volt gauge would always stay at 10 volts.Its been starting slow so i thought it was the battery and replaced it with optima red top. Still starts slow so replaced starter switch on drivers side fender, still turns over slow. So i think it is the starter that i just replaced a few months ago. But heres the problem that has stumped me, i have been trying to get it to quite surging for a while now, and found out that if i crank the car up and let it idle, it would surge, but if i take the positve battery cable off the surging quites and the volt gauge jumps to about 13 volts and the volt light comes soon as i touch the postive wire to the battery againg volts drop and surging starts again. I took my battery tester with load switch and left the car running with battery cable unhooked.put ground from battery tester to battery and positive battery tester lead to positive lead on car and when i hit the load switch the car cut off. Do you think the alternator is bad?
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Mar 10, 2000
Dublin GA
Sounds like a bad alternator to me. Drive to Advance Auto Parts or Auto zone & they will check it for free.

While you are in the mode to replace the alternator upgrade to a 130 amp alt from a 94-95 Mustang.

Here's websites with pictures of the 3G (94 Mustang and later 130 amp alt) installation procedure...

See - all the tech data you could ever want to know
OR - excellent pictures of installation

See these sites for the right way to do the wiring. Some people will tell you that you can skip the wiring upgrade, but it will catch up with you sooner or later. A fire in the wiring harness is ugly and expensive.

Under no circumstances connect the two 10 gauge black/white wires to the 3G alternator. If the fuse blows in the 4 gauge wire, the two 10 gauge wires will be overloaded to the point of catching fire and burning up the wiring harness.